A shuttle valve is a type of valve that allows fluid to flow therethrough from one of two fluid sources. Shuttle valves are used in pneumatic and hydraulic systems.
A shuttle valve may have a valve body defining three openings that represent a first inlet, a second inlet, and an outlet. A valve element moves freely within the valve body. When pressure from a fluid is exerted through a particular inlet, it pushes the valve element towards the opposite inlet. This movement may block the opposite inlet, while allowing the fluid to flow from the particular inlet to the outlet. This way, two different fluid sources can provide pressurized fluid to an outlet without back flow from one source to the other.
Further, when the valve element is pushed due to application of pressure from the particular inlet, the valve element may travel rapidly toward the other inlet. Such rapid movement may communicate high pressure fluid from the particular inlet to the outlet in a short period of time, thus causing pressure spike or a shock wave to travel downstream from the outlet. The shock wave may cause damage to components and lines disposed downstream from the outlet such as hoses, pressure sensors, other valves, etc.
Therefore, it may be desirable to have a shuttle valve with features that damp motion of the valve element so as to eliminate or mitigate the intensity of the pressure spike or shock wave travelling downstream from the outlet. Damping the movement of the valve element within the shuttle valve may improve the dynamics of an associated hydraulic or pneumatic system by reducing the pressure spikes caused when the shuttle valve switches from one source to the other. Such damping may prevent damage to fittings, sensors, seals, etc., and may also prevent erratic behavior of certain systems.